What are you talking about? V6 models were priced the same. MSRP for both cars was about $17,095. V6 models made up the majority of sales for both the F-body and the Mustang. The Mustang GT cost the same as the Z28/Trans-Am, and performed well under what the F-Body did. The Cobra cost the same if not more than the Z28 SS/WS6, and performed relatively the same. Try again.
IIRC the base price on the Mustang V6 was about $600 or $700 less than either F-body.
Also, IIRC the Mustang was available in convertable form for far less.
The GT and Z28/Trans-Am were basically equal in price, I do not debate that.
Value is solidly on the F-Body side in terms of engine and handling for these cars.
The Cobra was aroung $30K, while the SS/WS6 package brought the Z28/WS6 up about $4,000 from about $21,000.
My comment was about the majority of each car you see on the street: the base V6.